1. Field of the Invention
This invention relates to a mouth corner spreader used for spreading out the mouth corners at both ends of the lips for facilitating medical examination, treatment, photographing or other works in the mouth.
2. Description of the Prior Art
Among the conventional mouth corner spreading devices is known a type in which hooks are provided at the ends of the handle bars, and for opening the mouth corners by using such device, said hooks are attached to the mouth corners at both ends of the lips and an assistant pulls the handle bars to the right and left with his both hands. This type of mouth corner spreader, however, has the defect that an assistant is required for holding and operating the spreader, beside the person who makes the examination, treatment, photographing, etc., in the mouth.
There is also known another type of mouth corner spreader in which a spring arm is inserted into the mouth and the hooks are fastly attached to the mouth corners at both ends of the lips for effective positive spread-out of the mouth corners. This type of device still has some serious defects. That is, the spring arm which is inserted deed into the mouth in use of the spreader is obstructive to the prosecution of work such as examination, treatment, photographing, etc., in the mouth. Also, the presence of the spring arm in the mouth would give an unpleasant feeling of strangeness to the patient.